It is known to protect articles against theft by providing a detector in an area of a store which is actuated by an electronic signal circuit or a magnetic strip (compare U.S. Pat. No. 4,075,618) attached to the article. Such saftey arrangements are well-known for protecting clothing against theft, in which a tag is attached to the clothing with the aid of a clamp-like holder or with the aid of a spike. This tag or holder can only be removed with the aid of a special tool available to the sales personnel (compare for example German Patent Application laid open No. 2,539,035 and German Patent Application laid open No. 2,321,584). If, therefore, an article of clothing is carried out of the store without the tag or holder having been removed, then, the detector is actuated and emits an alarm signal.
On the other hand, the protection from theft of optically readable recorded discs, such as easily pocketed compact discs, presents a substantial problem.
Various proposals have been made for the protection against theft of such recorded disks. It is usual to store a compact disk in lockable display cases or presentation stands, or, alternatively, to display empty cassettes, the compact disk being stored in drawers located in the region of the cash register. These solutions entail a considerable expenditure with respect to organization and furnishings. In addition, these solutions are unsatisfactory, since it is not possible to open a cassette and to read an information sheet contained therein if the compact disks are locked in display cases or stands.
It is unfeasible to apply the above mentioned tags or holders to cassettes for compact disks since the cassettes can not be then be opened. If on the other hand a tag is applied to the cassette in a way similar to the way described in the U.S. Pat. No. 4,075,618, then, the cassette can still be opened and the compact disk taken out of the cassette, and, the empty cassette replaced. In this case theft would not be indicated by the store detector.